Energy Comparison of Fuels Paper In this laboratory exercise, you will learn how various sources of fuels are formed. You will also assemble a calorimeter and measure the heat released from two differ

Energy Comparison of Fuels Paper In this laboratory exercise, you will learn how various sources of fuels are formed. You will also assemble a calorimeter and measure the heat released from two differ
Exercise 1 Energy Content of Fuels In this exercise, you will construct a simple calorimeter to calculate the energy per mass of two fuels, isopropanol and paraffin wax. The energy content will be determined by burning each fuel and measuring the change in temperature of 100 mL of distilled water. Note: View the following video for a demonstration of using the digital scale before you continue the procedures. If needed, a descriptive text transcript is available. Using the Digital Scale Using the Digital Scale Volume 90%   ©© 2015 Science Interactive. All Rights reserved. Procedure Part 1: Calculating the Density (g/mL) of Water Note: Under standard conditions (1 atm pressure and 3.98°C), 1 mL of water has a mass of 1 gram. It is unlikely that you will be performing this experiment at standard conditions, so it is necessary to calculate the density of water at your location. Put on your gloves and goggles. Turn on the digital scale. Place the 25 mL graduated cylinder on the scale and tare the scale so that it displays 0.00g. Use the pipet to add 10.0 mL of distilled water to the graduated cylinder. See Figure 6.  © 2015 Science Interactive. All Rights reserved.Figure 6.  Distilled water added to the 10.0 mL line of the graduated cylinder. Record the mass of the water in Data Table 1. Calculate the density of the water using the equation: Density (g/mL)=Mass of water (g)Volume of water (mL)Density (g/mL)=Mass of water (g)Volume of water (mL) Record the density in Data Table 1. Place the thermometer in the water and measure the temperature to 0.1°C. Record the temperature of the water in Data Table 1. Part 2: Determining the Energy Content of Isopropanol Turn on the digital scale and tare it so that it displays 0.00 g. See Figure 7.  © 2015 Science Interactive. All Rights reserved.Figure 7.  Tared scale displaying 0.00 g. Remove the cap from the refillable alcohol canister, weigh the canister, and record the mass in Data Table 2. Disassemble the refillable alcohol by unscrewing the threaded connector and then removing the wick. See Figure 8.  © 2015 Science Interactive. All Rights reserved.Figure 8.  Fuel canister disassembly. Place the plastic funnel in the opening of the refillable alcohol canister. See Figure 9.  © 2015 Science Interactive. All Rights reserved.Figure 9.  Funnel in refillable alcohol canister. Use the graduated cylinder and a pipet to measure 25.0 mL of 70% isopropanol. Pour the 25.0 mL of isopropanol into the canister using the funnel. See Figure 10.  © 2015 Science Interactive. All Rights reserved.Figure 10.  Adding fuel to refillable alcohol canister. Measure 5.0 mL 70% isopropanol and add this to the canister so that it contains a total of 30.0 mL isopropanol. Reassemble the canister by removing the funnel, placing the wick inside the opening, and screwing in the connector. See Figure 11.  © 2015 Science Interactive. All Rights reserved.Figure 11.  Reassembled fuel canister. Turn on the digital scale and tare it so that it displays 0.00 g. Place the canister containing the isopropanol on the scale. Determine the initial mass of the fuel by subtracting the mass of the canister containing alcohol from the mass of the empty canister and record in Data Table 2. Place an aluminum pie plate on a solid work surface away from flammable objects.  Use the graduated cylinder and pipet to measure 25.0 mL of distilled water. Transfer the water into the 250 mL glass beaker. Repeat steps 21–22 three times so that the glass beaker contains 100.0 mL of distilled water. Place the analog thermometer into the water and allow it to equilibrate. Use a pair of scissors and a ruler to create a 20 cm x 20 cm square of aluminum foil and place it on top of the beaker. Position the burner stand towards the back of the pie plate.  Place the covered beaker containing the water and thermometer on the burner stand. Position the alcohol canister containing the 30.0 mL of isopropanol in front of the burner stand. Note: The height of the wick must be below the burner stand so the flame does not extinguish when lit. Set the aluminum cup next to the refillable alcohol canister setup so that it can be used to extinguish the flame at any point. See Figure 12.  © 2015 Science Interactive. All Rights reserved.Figure 12.  Experimental setup with alcohol canister, burner stand, and beaker assembly. Record the initial temperature of the water in Data Table 2.  Use matches or a lighter to ignite the wick of the fuel canister.  Gently slide the fuel under the stand without disturbing the beaker. See Figure 13.  © 2015 Science Interactive. All Rights reserved.Figure 13.  Ignited refillable alcohol canister positioned under the burner stand. Set a timer for 5:00 minutes using either a stop watch or timer.  After 5 minutes, use the 2 oz. aluminum cup to extinguish the fuel canister flame. See Figure 14.  Note: Do not touch the metal stand or the beaker as they may be hot.  © 2015 Science Interactive. All Rights reserved.Figure 14.  Using the aluminum cup to extinguish the alcohol canister flame.  Carefully move the fuel canister from underneath the burner stand. Note: The sides of the burner fuel canister will be warm to the touch, but not hot.  Remove the aluminum cover from the beaker. Stir the water in the beaker with the thermometer until the temperature equilibrates. Record the temperature in Data Table 2. Allow the beaker to cool before pouring the water down the drain. Remove the metal cup from the alcohol canister and weigh the canister on the digital scale. Record the final mass in Data Table 2. Part 3: Determining the Energy Content of Paraffin Wax Repeat steps 21–27 using fresh distilled water. Turn on the digital scale and tare it so that it displays 0.00 g. Place the tea candle on the scale and record the mass in Data Table 2. Position the test tube holder in front of the burner stand and place the tea candle on top of the test tube holder. See Figure 15.  © 2015 Science Interactive. All Rights reserved.Figure 15.  Experimental setup with candle placed on top of test tube rack, burner stand, and beaker assembly. Record the temperature of the water in Data Table 2. Use matches or a lighter to ignite the candle wick.  Gently slide the burning candle under the stand without disturbing the beaker. See Figure 16.  © 2015 Science Interactive. All Rights reserved.Figure 16.  Burning tea candle positioned under burner stand. Set a timer for 5:00 minutes.  After 5 minutes, use the 2 oz. aluminum cup to extinguish the candle flame. See Figure 17.  © 2015 Science Interactive. All Rights reserved.Figure 11.  Using the aluminum cup to extinguish the candle flame.  Remove the foil from the beaker and stir the water with the thermometer. Record the temperature in Data Table 2. Note: Read the temperature without touching the thermometer to the sides or bottom of the beaker. Allow the beaker to cool before pouring the water down the drain. Remove the metal cup from the candle and weigh the candle on the digital scale. Record the final mass of the burned candle in Data Table 2. Calculate the ΔT for each fuel type by subtracting the initial temperature from the final temperature and record in Data Table 3. Calculate the number of calories of energy absorbed by the water (Q), using the equation: Q=ΔT × m ×cpQ=ΔT × m ×cp Note: Use the density of water you determined in Data Table 1 to calculate the mass of 100.0 mL of water. Record the value for Q (calories) for each fuel type in Data Table 3.  Calculate the total mass of fuel consumed by subtracting the final mass from the initial mass.  Record the total consumed mass of each fuel in Data Table 3. Calculate the amount of energy in calories released per gram of fuel using the equation: Calories per Gram=Q (cal)Mass of Fuel consumed (g)Calories per Gram=Q (cal)Mass of Fuel consumed (g) Record the energy values for each fuel in Data Table 3. Note: For these calculations, is is assumed that all heat released by the fuel was absorbed by the water. Exercise 1 – Questions Question 1 Which fuel was more efficient (produced more calories per gram)? Explain your answer. Question 2 Explain the difference in the efficiencies of the fuels you tested based on the chemical structures of the fuels. Question 3 Diethylene glycol is an organic compound used as a fuel in heating cans.  Based on its structure and your data recorded in Data Table 3, how do you hypothesize its energy efficiency (cal/g) compared to isopropanol and paraffin wax? Question 4 What are the possible sources of error in this experiment? How could the errors be reduced in future experiments?
Energy Comparison of Fuels Paper In this laboratory exercise, you will learn how various sources of fuels are formed. You will also assemble a calorimeter and measure the heat released from two differ
Table 1: mass and density of distilled water *Mass of 10ml of distilled water The density of water(G/ML) Temperature 9.6 .96 20 Table 2: calorimetric data *Fuel source Empty fuel canister Fuel canister (isopropanol/water) 41.42g Tea candle(paraffin) *Fuel source The initial mass of fuel (g) Fuel canister (isopropanol/water) 246.5 Tea candle(paraffin) 17 -*Fuel source The final mass of fuel (g) Fuel canister (isopropanol/water) 239.6 Tea candle(paraffin) 16.5 *Fuel source Initial temperature (0 c) Fuel canister (isopropanol/water) 20 Tea candle(paraffin) 21 T *Fuel source Final temperature (o c) Fuel canister (isopropanol/water) 87 Tea candle(paraffin) 29 Table 3: calories released per gram of fuel *Fuel source Temperature change (o c) Fuel canister (isopropanol/water) 67 Tea candle(paraffin) 8 *Fuel source Calories absorbed by water (cal) Fuel canister (isopropanol/water) 12.864 Tea candle (paraffin) 1.536 *Fuel source Grams of fuel consumed (g) Fuel canister (isopropanol/water) 6.9 Tea candle(paraffin) 0.5 *Fuel source Calories/grams Fuel canister (isopropanol/water) 1864.3 Tea candle(paraffin) 3072